Rope manufacturing process



March 21, 195? H. A. HOOD ROPE MANUFACTURING PROCESS Filed NOV. 15, 1965 :0 .4 JPIL 4 H. A. HOOD ATTORNEYS United States Patent Ofiice 3,3@9,86Z Patented lVIar. 21, 1967 3,309,862 ROPE MANUFACTURING PROCESS Henry A. Hood, Moorestown, NJ., assignor to Wall Industries, Inc., a corporation of Delaware Filed Nov. 15, 1965, Ser. No. 507,856 Claims. (Cl. 57-460) This invention relates to rope and similar cordage formed from synthetic materials.

Synthetic ropes employed in maritime industries utilize nylon, polypropylene, polyethylene, polyesters and similar fibers alone or in various combinations. These ropes have many advantages over natural fibers.

One rope of particular interest is that which employs a plurality of outer or surface yarns around a central core for each strand of the rope. The surface yarns are composed of at least one bundle of monofilament plastic fibers around which is wrapped a plurality of multifilament plastic fibers. Monofilament fibers are those in which each fiber is a single, solid, continuous string of material and has a diameter usually in excess of about 4 mils. Multifilament fibers have a diameter less than about 4 mils.

Although synthetic ropes of this type of construction have good coefficients of friction, they also exhibit a stick-slip characteristic until broken in by use. The stick-slip characteristic is observed during rendering of the rope over a capstan, bitt or other retaining surface in a manifestation that the rope tends to alternately grip and suddenly release and then regn'p the retaining surface.

It has now been found that this stick-slip characteristic can be removed and therefore the rendering properties of the synthetic rope improved by scuffing the surface of the strands which are used to make up the rope. The scufiing, scraping, and/or disorientation of at least the multifilaments on the outside of the strand forms a nap or fuzziness on the surface of the rope and at least some crosslaying of the multifilaments over that surface.

Accordingly, it is an object of this invention to provide a new and improved synthetic rope.

Other aspects, objects and the several advantages of this invention will be apparent to those skilled in the art from the description, drawing and appended claims.

FIGURE 1 discloses a rope embodying this invention.

FIGURE 2 shows a cross-section of the rope of FIG- URE 1.

FIGURE 3 shows apparatus for producing the rope of FIGURE 1 according to this invention.

FIGURE 4 shows a large cross-section of core yarns and outer yarns embodying a preferred aspect of this invention.

In FIGURE 1 there is shown a rope 1 composed of three separate strands, 2, 3, and 4, Wrapped about one another in a conventional manner. Each strand has surface yarns 5a, 5b, and so on around its periphery, each yarn being composed of one or more bundles of monofilaments, e.g. polyethylene monofilaments, having, for example, diameters of from about 4 to about mils about which is wrapped a plurality of multifilaments, e.-g. polyester multifilaments, each multifilament having, for example,, a diameter of from about 1 to about 3 mils. The combination of polyolefin monofilaments surrounded by polyester multifilaments has been found to be particularly advantageous and useful in this invention.

FIGURE 2 shows a cross-section of strands 2, 3, and 4 wherein circular lines describe the locus for the surface yarns 5a and 5b, 6a and 6b, and 7a and 7b of strands 4, 2, and 3, respectively. The core yams 8, 9, and 10 of the strands can be made up of combinations of filaments similar to the surface yarns or, preferably, other types and/or combinations of filaments such as complete use of monofilaments, e.g. polypropylene. The core yarns are preferably formed from twisting two or more bundles of mon-ofilaments together.

Generally, any suitable plastic material can be em ployed'as the fibers in the yarns, for example, besides the above-mentioned plastics, polyamides, polyimides, and the like, and copolymers utilizing two or more similar or different plastic monomers, and the like can be employed. These fibers are well known to those skilled in the art and can be obtained commercially. Methods of making these polymers and vendors of the polymers and fibers that can be employed in this invention are known widely, see Modern Plastics Encyclopedia issue for 1965, volume 42, No. 1A, published by McGraW- Hill, Inc.

FIGURE 3 shows a conventional strand former tube or sizing die 10 well known to those skilled in the ropemaking art through which rope yarns, for example core yarns 9 and surface yarns 6 are passed and wrapped into a single strand 2. The strand then passes to a conventional former fiyer 11 for subsequent wrapping with other strands to form the finished rope. Between die 10 and former fiyer 11 strand 2 is brushed by rapidly rotating wire brush 12 to cause scuffing of at least the multifilaments on the surface of the strand thereby [forming a nap, i.e. fuzzy or hairy surface, on strand 2. If desired, the appearance of the nap can be improved by employing a second brush 13 preferably formed of a synthetic material such as nylon. This optional dressing brush 13 causes, in part, cross laying of the scuffed multifilaments and the like. The brush of brushes are rotated by motor 14 which is operatively connected to shaft 15 through pulleys 16 and 17 and pulley belt 18.

In FIGURE 4, sub-FIGURE 4a shows a core yarn 10 which cross-section shows a plurality of monofilaments of polypropylene wrapped about one another. It is even more preferred that each core yarn be composed of a plurality of separatet bundles of polypropylene monofilaments, these bundles being wrapped about one another to form the core yarn.

Sub- IGURE 4b shows an outer yarn having an inner area 20 of polypropylene monofilaments or bundles of monofilaments wrapped about one another and an outer area 21 composed of a plurality of bundles of multifilaments of polyester such as polyethylene terephthalate wrapped around the outer surface of the polypropylene area 20. Each yarn of multifilaments is preferably composed of a plurality of very fine polyester fibers.

EXAMPLE A strand is formed comprising a core of twisted polypropylene bundles of monofilaments 10 mils in diameter, the core having an outside diameted of about inch, and around the core is wrapped 57 surface yarns twisted together in groups of three. Each surface yarn is composed of a plurality of monofilaments of polyethylene of 12 mil diameter, the diameter of the monofilament section being about 0.065 inch, around which is wrapped a plurality of fine filaments of polyethylene terephthalate, these filaments having a diameter of 1.5 mils. Each surface yarn has an outside diameter of about A inch. The strand has an outside diameter after the surface yarns have been Wrapped around the core of about 1 inch. The strand is passed at a rate of feet per minute in contact with a rotating wire brush 6 inches in diameter by 8 inches long and rotating at 2400 revolutions per minute, its long axis being parallel to the long axis of the strand. The strand is then layed together with three other similarly formed and similarly scufied strands to produce a finished rope. The finished rope when put into use exhibits substantially no sticks lip characteristic even during its period of first use.

Reasonable variations and modifications are possible within the scope of this disclosure Without departing from the spirit and scope thereof.

I claim:

1. In the production of a rope by wrapping a plurality of strands about one another, said strands having a plurality of yarns at least on the outer surface thereof, each yarn being composed of at least a plurality of multifilament plastic fibers, the improvement comprising scutfing said strands before laying same into a rope.

2. The method according to claim 1 wherein said strands are composed of a core and a plurality of surface yarns wrapped about said core, at least the surface yarns of said strands each being composed of at least one bundle of monofilament plastic fiber around which is wrapped a plurality of multifilament plastic fibers, and wherein the improvement comprises sculfing the outer surface of said strands before laying same into a rope.

3. The method according to claim 1 wherein said strands are composed of a core of a plurality of wrapped bundles of plastic fibers, and a plurality of outer yarns wrapped about said core, the outer yarns of said strands each being composed of at least one bundle of monofilament plastic fiber around which is wrapped a plurality of multifilament plastic fibers, and wherein the improvement comprises scufling a substantial portion of the peripheral surface of said strands before laying same into a rope thereby forming a nap on said peripheral surface of said strands.

4. The method according to claim 1 wherein said strands are composed of a core of wrapped polypropylene bundles, and a plurality of surface yarns wrapped about said core, said surface yarns each being composed of a plurality of monofilaments of polyethylene wrapped about one another and around which plurality is wrapped a plurality of multifilament polyester fibers, and wherein the improvement comprises scrapping the surface of said strands to break and disorient at least some of said multifilaments to form a nap on said strands before laying same into a rope thereby improving the rendering characteristics of the finished rope.

5. The method according to claim 4 wherein said polyester is polyethylene terephthalate.

References Cited by the Examiner UNITED STATES PATENTS 2,241,206 5/1941 Koster 2867 X 2,244,333 6/1941 Hanse 2867 X 2,456,804 12/1948 Winslow 34-154 3,026,669 3/1962 Stanton 57153 X 3,111,001 11/1963 Schmittmann et al. 57160 X 3,140,526 7/1964 Tlamicha 2867 3,158,983 12/1964 Tlamicha 28-67 X 3,229,347 1/ 1966 Tlamicha 2867 3,274,765 9/1966 Hurtmann et al. 5714O X FRANK J. COHEN, Primary Examiner.

D. E. WATKINS, Assistant Examiner. 

1. IN THE PRODUCTION OF A ROPE BY WRAPPING A PLURALITY OF STRANDS ABOUT ONE ANOTHER, SAID STRANDS HAVING A PLURALITY OF YARNS AT LEAST ON THE OUTER SURFACE THEREOF, EACH YARN BEING COMPOSED OF AT LEAST A PLURALITY OF MULTIFILAMENT PLASTIC FIBERS, THE IMPROVEMENT COMPRISING SCUFFING SAID STRANDS BEFORE LAYING SAME INTO A ROPE. 